Subject: TH22AT KENWOOD HT MOD
Subject: KENWOOD TH22AT extended frequency operation.
This procedure will expand the capabilities from 136.000 to 173.995 MHz.
PROCEDURE:
1. Turn off power and remove battery pack.
2. Remove antenna and two knobs from top of unit.
3. Gently pry the rubber escutcheon off the top of the unit.
4. Remove the two long screws from the rear of the radio case.
5. Squeeze the bottom of the front panel together and gently separate
the two case halves. Use caution so as to not damage the thin
ribbon cable connecting the front panel to the main unit.
6. Remove diode D208 located on the circuit board behind the front
panel.
7. Place the diode just removed in the location shown for diode D212
and solder in place. Observe proper polarity. The diode should
face the same direction as diodes D210 and D211.
8. Reverse steps 1-5 to reassemble.
9. Reset the microprocessor.
CAUTION: This modification requires soldering equipment rated for CMOS
type circuits. It also requires familiarity with surface mount soldering
techniques. If you do not have the proper equipment or knowledge do not
attempt this modification yourself. Seek qualified assistance.
PHYSICAL LOCATIONS
! ======== W201
!
TOP ! ======== W202
!
! __________________
! ! ! [D206] [D210]
----------------------- !
! ! [D207] [D211]
! CN203 !
! ! [D208] (D212)
thin ribbon ! !
! ! (D213)
! !
------------------------ !
! ! !
! ------------------ ___________
! __________! !
!_______________________________!__SPKR___!___MIC____!________
X57-4370-11 (B/4)
==========================================================================
Most of this information was taken from a bulletin I received from KC7AOF.
Several Mods have proven this alteration accurate and effective.
SOURCE: The QRZ Windows Ham Radio CDROM | 
